An integrated silicon and III-N semiconductor device may have electronic components such as metal oxide semiconductor (MOS) transistors formed in silicon, and other electronic components such as gallium nitride field effect transistors (GaN FETs) or optoelectronic components such as photodetectors, light emitting diodes (LEDs) or lasers formed in III-N semiconductor material, with the silicon and III-N semiconductor material disposed on a common substrate. It may be desirable to integrate the silicon and III-N semiconductor material on a common substrate prior to fabricating the components in the silicon and in the III-N semiconductor material.